Crustless Spinach Quiche
- Non-stick cooking spray
- 1 tablespoon olive oil
- 1 onion, chopped
- 1 (10-ounce) package frozen chopped spinach, thawed and drained
- 5 eggs, beaten
- 3 cups shredded Muenster cheese (or soft white cheese of choice)
- 1/4 teaspoon salt
- 1/8 teaspoon ground black pepper